This invention relates to a switch having a snap-action system and a switching rocker for use in motor vehicles.
Switches having a snap-action system have been increasingly used in modern motor vehicles, because these switches are advantageous with regard to their switching performance and service life. German specification AS No. 2,122,403 describes a switch of this kind with a snap-action system which is constructed as a toggle switch. In this known example the snap spring is supported in a stationary knife-edge bearing. At the opposite side the snap spring is clamped in a swivellable operating element, wherein the operating element is designed as an actuating element. Thus the switching motion is conducted into the snap spring at one end, whereby, due to the firm clamping of the snap spring in this operating element, the bending during the changeover of the snap spring is predetermined. During the changeover the snap spring will bend in the manner of an S, which is an advantage, because, when the changeover is initiated, the contact pressure is at first increased. This has a favorable effect on the service life and the switching performance of the switch.
However, this known switch cannot be used in all cases, because a push-button switch is often necessary instead of a toggle switch. A push-button switch with a snap-action switching system is, for example, known from the German patent No. 3,039,419. In this known example the linear motion of the operating element formed as a push-button is transmitted onto the movable contact reed by way of a star wheel having a control cam. Thus the switching force is not directly conducted into one end of the snap spring. In a push-button switch of this kind the switching forces for changing over the snap-action system differ, because the cam body acts upon the contact reed by means of lever arms with different lengths. This unbalanced changeover feeling is often objected to by the users.
Thus the object of the present invention is to create a parking position switch with a snap-action switching system as favorably priced as possible, and in which system equal switching forces in both switching directions are necessary for a changeover.